:mod:`htmllib` --- A parser for HTML documents
==============================================
.. module:: htmllib
:synopsis: A parser for HTML documents.
:deprecated:
.. deprecated:: 2.6
The :mod:`htmllib` module has been removed in Python 3.
Use :mod:`HTMLParser` instead in Python 2, and the equivalent,
:mod:`html.parser`, in Python 3.
.. index::
single: HTML
single: hypertext
.. index::
module: sgmllib
module: formatter
single: SGMLParser (in module sgmllib)
This module defines a class which can serve as a base for parsing text files
formatted in the HyperText Mark-up Language (HTML). The class is not directly
concerned with I/O --- it must be provided with input in string form via a
method, and makes calls to methods of a "formatter" object in order to produce
output. The :class:`~HTMLParser.HTMLParser` class is designed to be used as a base class
for other classes in order to add functionality, and allows most of its methods
to be extended or overridden. In turn, this class is derived from and extends
the :class:`SGMLParser` class defined in module :mod:`sgmllib`. The
:class:`~HTMLParser.HTMLParser` implementation supports the HTML 2.0 language as described
in :rfc:`1866`. Two implementations of formatter objects are provided in the
:mod:`formatter` module; refer to the documentation for that module for
information on the formatter interface.
The following is a summary of the interface defined by
:class:`sgmllib.SGMLParser`:
* The interface to feed data to an instance is through the :meth:`feed` method,
which takes a string argument. This can be called with as little or as much
text at a time as desired; ``p.feed(a); p.feed(b)`` has the same effect as
``p.feed(a+b)``. When the data contains complete HTML markup constructs, these
are processed immediately; incomplete constructs are saved in a buffer. To
force processing of all unprocessed data, call the :meth:`close` method.
For example, to parse the entire contents of a file, use::
parser.feed(open('myfile.html').read())
parser.close()
* The interface to define semantics for HTML tags is very simple: derive a class
and define methods called :meth:`start_tag`, :meth:`end_tag`, or :meth:`do_tag`.
The parser will call these at appropriate moments: :meth:`start_tag` or
:meth:`do_tag` is called when an opening tag of the form ```` is
encountered; :meth:`end_tag` is called when a closing tag of the form ````
is encountered. If an opening tag requires a corresponding closing tag, like
``

`` ... ``

``, the class should define the :meth:`start_tag` method; if
a tag requires no closing tag, like ``

``, the class should define the
:meth:`do_tag` method.
The module defines a parser class and an exception:
.. class:: HTMLParser(formatter)
This is the basic HTML parser class. It supports all entity names required by
the XHTML 1.0 Recommendation (https://www.w3.org/TR/xhtml1). It also defines
handlers for all HTML 2.0 and many HTML 3.0 and 3.2 elements.
.. exception:: HTMLParseError
Exception raised by the :class:`~HTMLParser.HTMLParser` class when it encounters an error
while parsing.
.. versionadded:: 2.4
.. seealso::
Module :mod:`formatter`
Interface definition for transforming an abstract flow of formatting events into
specific output events on writer objects.
Module :mod:`HTMLParser`
Alternate HTML parser that offers a slightly lower-level view of the input, but
is designed to work with XHTML, and does not implement some of the SGML syntax
not used in "HTML as deployed" and which isn't legal for XHTML.
Module :mod:`htmlentitydefs`
Definition of replacement text for XHTML 1.0 entities.
Module :mod:`sgmllib`
Base class for :class:`~HTMLParser.HTMLParser`.
.. _html-parser-objects:
HTMLParser Objects
------------------
In addition to tag methods, the :class:`~HTMLParser.HTMLParser` class provides some
additional methods and instance variables for use within tag methods.
.. attribute:: HTMLParser.formatter
This is the formatter instance associated with the parser.
.. attribute:: HTMLParser.nofill
Boolean flag which should be true when whitespace should not be collapsed, or
false when it should be. In general, this should only be true when character
data is to be treated as "preformatted" text, as within a ``